1. Field of the Invention
The invention relates to the field of pool cleaning systems.
The invention particularly relates to pool cleaning systems wherein pop-up water actuated jet cleaning devices are mounted flush with the interior surface of the swimming pool.
The invention specifically relates to the field of pool cleaning apparatus wherein the actuation of pop-up jets is a graded, non-abrupt actuation and the fluid flow rate through the pool cleaning system is maintained constant to prevent water hammer pressure surges which can be deleterious to the system.
2. Prior Art
In-pool cleaning systems are well known in the prior art. Miller, in U.S. Pat. No. 3,247,969, and Werner, in U.S. Pat. No. 3,449,772, provide water jet heads which are permanently emplaced a slight distance above the interior surface of a pool. Werner also introduces a flush mounted pop-up jet head which offers no obstruction to a pool user when the cleaning system is in operation.
Others also have disclosed pop-up rotating jet heads which are embedded nominally flush with the interior surface of the pool. Such disclosures will be found in Ghiz, U.S. Pat. No. 3,521,304; in Mathews U.S. Pat. Nos. 4,202,499 and 4,271,541, as well as 4,347,979, and 4,371,994. Another rotary pop-up jet is disclosed by Gould in U.S. Pat. No. 4,322,860. All of these latter noted pop-up rotary jet heads are characterized by the complexity of the mechanism required for establishing the rotation of the jet heads.
Two recent and surprisingly similar U.S. patents disclose pop-up jet heads of significantly reduced complexity when compared with the prior art. These are the patents to Carter, U.S. Pat. No. 4,188,673 and that to Goettl et al, U.S. Pat. No. 4,212,088. Yet as uncomplex a device as these latter pop-up heads present, they still present an assemblage of items which are subject to failure under the constant, abrupt, battering by the pop-up head with the interfering stop elements of the housings.
It is therefore an objective of the invention to provide a hydraulically actuated pop-up cylinder of less complex design than that of the prior art.
It is a further objective of the invention to provide a system in which hydraulically actuated cores are reciprocated outward from a housing by a graded, non-abrupt application of fluid pressure to the device.
It is another objective of the invention to provide an in-floor pool cleaning system having gradedly, non-abruptly actuated pop-up heads with improved jet stream means, the effect of the improved jet stream means being more efficient movement into suspension of matter in close proximity to the jet head as well as reducing the leakage of pressurized water from potential voids which may exist between the housing and the pop-up head when the jet is in operation.
A further objective of the invention is the provision of means for maintaining a constant rate of flow of fluid through the system so that, unlike prior art systems, there are no water hammer, pressure surges in the system, which water surges not only frequently lead to failure of the pop-up head assemblies but to plumbing and equipment failures at other points throughout the pool cleaning, filtering and water circulation systems.